The present invention relates to a vehicle occupant protection system, and is particularly directed to a system that includes a weight sensor and a distance sensor.
Occupant protection systems for use in vehicles are known in the art. One protection system type includes an actuatable inflatable restraint module, which has an inflatable restraint that is commonly referred to as an air bag. A controller determines whether the restraint module is to be actuated to inflate the air bag within a vehicle passenger compartment. The restraint module is actuated by the controller upon the occurrence of a predetermined condition for which a vehicle occupant is to be restrained. For example, the restraint module is actuated when a crash sensor that is operatively connected to the controller senses a vehicle condition indicative of a vehicle crash condition.
Protection system devices, such as an inflatable restraint module, that have one or more adjustable aspect(s) to enhance protection device performance are also known. Adjustment (i.e., control) of the adjustable aspect(s) is based upon one or more sensed condition(s). Such a protection device that is a restraint module is commonly referred to as a xe2x80x9csmart restraint.xe2x80x9d
For example, in a known inflatable restraint modules the dynamic deployment profile of the air bag is adjustable. Specifically, with regard air bag deployment profile it is known to adjust the inflation timing, the inflation pressure, and the positioning of the inflating air bag. Further, suppression of actuation of the air bag is also an adjustable aspect.
Often, adjustment of the protection system device is based upon one or more sensed occupant condition(s). For example, adjustment of the dynamic deployment profile (e.g., inflation timing, inflation pressure, or complete suppression) of an air bag is controlled based upon a position or location of an associated occupant at the time of a vehicle crash condition. It is also known to control the dynamic deployment profile of an air bag based upon occupant size (e.g., large versus small) and occupant type (e.g., adult versus child).
Various types of occupant characteristic sensors are known to sense occupant characteristics such that appropriate determinations can be made with regard to control of a protection system device. For example, distance or ranging sensors are used to sense distance to a surface associated with the occupant. Using geometry, the location of the occupant is related to a structure within the vehicle, such as a distance between an air bag module and the occupant.
With regard to air bag modules, it is known to xe2x80x9cde-powerxe2x80x9d actuation of an air bag module or to completely suppress actuation of the module if a head/thorax/torso of an associated vehicle occupant is located such that a full power actuation of the module will not enhance protection of the occupant. Thus, distance measurements/calculations are typically desired to be related the head/thorax/torso of an associated vehicle occupant to the air bag module.
Known distance sensors include ultrasonic, infrared, and capacitive-based sensors. However, certain conditions may cause difficulty for the distance sensor in making an accurate distance measurement to the head/thorax/torso of the occupant. For example, an ultrasound or infrared sensor may perceive a distance to a hand/arm of an occupant, a book, a newspaper, or the like that is located between the distance sensor and the head/thorax/torso of the occupant. Also, heavy clothing may cause difficulty for making an accurate distance determination for systems that have an ultrasound or infrared sensor. With regard to a capacitive-based distance sensor, a hand/arm of an occupant could cause difficulty in making an accurate distance determination.
Weight sensing of the occupant is useful to provide information regarding the presence, size, and type of the occupant. However, such determinations do not remedy the difficulty in making accurate distance determinations.
In accordance with one aspect, the present invention provides a vehicle occupant protection system. The system includes an occupant protection device. Means senses a weight value associated with an occupant. Means determines a weight-based center characteristic associated with the occupant using the sensed weight value. Means senses a distance to a surface associated with the occupant. Control means controls the protection device utilizing the determined center characteristic and the sensed distance. The control means includes means for determining whether the sensed distance is to a surface of a head/thorax/torso of the occupant utilizing the determined center characteristic.
In accordance with another aspect, the present provides a vehicle occupant protection system. The system includes an occupant protection device. A plurality of weight sensors of the system are associated with a vehicle seat. Each sensor senses a weight value associated with an occupant located on the seat. Means of the system determines center of gravity associated with the occupant using the sensed weight values. Means senses a distance to a surface associated with the occupant. Control means controls the protection device. The control means includes means for determining control of the protection device utilizing the determined center of gravity and the sensed distance.
In accordance with another aspect, the present provides a method of protecting a vehicle occupant. A weight value associated with an occupant is sensed. A weight-based center characteristic associated with the occupant is determined using the sensed weight value. A distance to a surface associated with the occupant is sensed. An occupant protection device is controlled utilizing the determined center characteristic and the sensed distance. The control includes determining whether the sensed distance is to a surface of a head/thorax/torso of the occupant utilizing the determined center characteristic.